Molecular design of nonlinear optical (NLO) polymeric materials for device application such as ultrafast optical switches are discussed. It is necessary to fabricate channel waveguides to realize polymeric NLO switching devices that can be driven with lower laser power. For that purposes, we have proposed a molecular structure of processable NLO polymers where the reduction of an attenuation loss and the attainments of higher processability of the polymers are achieved. Third-order nonlinear optical properties, chi((3)), of novel NLO polymers were around 10(-10) esu at 1.5 mu m wavelength region. Even in off-resonant regions, their chi((3)) values are around 5 x 10(-11) esu. Single mode channel waveguides of the polymers are fabricated using a standard photo-process. Attenuation loss through the film and that far the single mode waveguide at 1.32 mu m wavelength was also reported.